Morse code translator

Type text on the left to get Morse on the right. Going the other way, separate letters with spaces and words with a slash, the format the converter itself produces.

The controls underneath play the message rather than printing it. Play sound sends it as a tone. Flash light blinks it inside the button, small and capped at three flashes a second so it's safe to watch. Speed sets how long one unit lasts and Tone sets the pitch; Download .wav saves the audio at whatever you've chosen, which is how most people practise.

Everything is built on one unit of time. A dot lasts one unit, a dash three. Gaps run one unit inside a letter and three between letters. Seven between words. The tempo can change but those proportions can't, which is how two operators at different speeds still understand each other.

Speed is measured against the word PARIS, whose dots, dashes and gaps come to exactly 50 units. Send PARIS 20 times in a minute and you're sending at 20 words per minute. Beginners work at 5 to 15.

Samuel Morse and Alfred Vail built the code for the electric telegraph in the 1830s and 1840s. The international version settled in 1865. The design is smarter than it first appears: E, the commonest letter in English, is one dot, while Q and Y run to four symbols. Morse shortened what operators would send most, which is the same instinct behind every compression scheme since.

The Titanic's operators sent the old distress call CQD and the new SOS on the same night in 1912, and the newer one stuck. The French Navy closed its Morse watch on the last day of 1996 with a line nobody has improved on: "Calling all. This is our last cry before our eternal silence."

Amateur radio operators still use it. So do aviation navigation beacons, which identify themselves in Morse on a loop to anyone tuned in.

A telegraph key has two states, on and off, and binary answers the same question inside a computer with two digits instead of three durations.

For alphabets rather than signals, runes and Ogham swap the letters and keep the words. And if you've been handed something unreadable that might not be Morse at all, the cipher identifier will tell you.